$OpenBSD: patch-third_party_zlib_BUILD_gn,v 1.2 2017/04/19 05:16:47 robert Exp $
--- third_party/zlib/BUILD.gn.orig.port	Mon Aug 15 21:10:46 2016
+++ third_party/zlib/BUILD.gn	Mon Aug 15 21:10:52 2016
@@ -115,7 +115,7 @@ static_library("minizip") {
       "contrib/minizip/iowin32.h",
     ]
   }
-  if (is_mac || is_ios || is_android) {
+  if (is_mac || is_ios || is_android || is_openbsd) {
     # Mac, Android and the BSDs don't have fopen64, ftello64, or fseeko64. We
     # use fopen, ftell, and fseek instead on these systems.
     defines = [ "USE_FILE32API" ]
